Ampoule applicator



Feb. 22, i965 R, P, DUNMiRE 3,236,237

AMPOULE APPLICATOR Filed Jan. l5, 1963 2 Sheets-Sheet 1 ATTORNEYS Feb. 22, 1966 R. P. DUNMIRE AMPOULE APPLICATOR 2 Sheets-Sheet 2 Filed Jan. l5, 1963 INVENTOR.

ATTORNEYS United States Patent O 3,236,237 AhPOULE APPLICATOR Russell P. Dunmire, deceased, late of Chagrin Falls, Ohio, by Hannah Dunmire, executrix, 29550 Pike Drive, Chagrin Falls, Ohio Filed Jan. 1S, 1963, Ser. No. 252,274 6 Claims. (Cl. 12S-216) This invention relates generally to applicators for hypodermic ampoules and related devices. More particularly, the invention relates to improvements in applicators for use with disposable hypodermic ampoules designed to give injections into or below the skin or human beings and other animals.

The hypodermic ampoules for which the applicators of this invention are designed are characterized by a shell dening a liquid reservoir having a generally flat and easily punctured end Wall. The other end of the shell is relatively rigid and supports the butt end of a hypodermic needle that is enclosed Within the shell, the butt end being in liquid communication with the reservoir and the shank yor cannula extending substantially perpendicularly to the end Wall to be punctured. The ampoule is actuated by collapsing it to force the needle cannula through the generally flat end wall of the shell and into the patient while expelling liquid from the shell through the needle.

Hypodermic ampoules of the type refer-red to are the subjects of U.S. Patents Nos. 2,696,212 land 2,769,434 and pending U.S. applications Serial Nos. 138,999 and 139,000, filed September 18, 1961, and now issued as Patent No. 3,094,987 and Patent No. 3,094,988, respectively, all being granted to Russell P. Dunmire (now deceased) as the inventor.

Such hypodermic ampoules are used by placing the generally at end Wall against or closely adjacent the skin of the patient and simply collapsing the ampoule shell by externally applied force. During the initial collapsing movement, while the liquid medicament is confined in the shell, the pointed end of the needle cannula punctures the generally flat end Wall of the shell. During the remainder of the collapsing action, the needle is forced into the patient, and the medicament in the ampoule is exhausted through the needle as the interior volume of the ampoule is reduced by the collapsing of the shell. These hypodermic ampoules were originally intended to be collapsed manually, as by thumb pressure.

In order to insure injection of an accurately predetermined amount of liquid medicament from ampoules of the type described, they are preferably substantially lled with the liquid, leaving little or no space occupied by compressi'ble air or other gas. This has created problems in designing the ampoule so that it can still be collapsed. Unless relative movement of the pointed end of the needle into and through the adjacent end Wall of the shell occurs before the confined, incompressible liquid completely lls and prevents further reduction in volume of the ampoule, an hydraulic lock may occur and prevent Ifurther collapsing of the shell until it bursts or is so distorted from its initial configuration that it does not have the particular collapsing action for which it Was designed. This problem, among others, led to the development of an ampoule end wall or diaphragmf as it is called, that has a central, outwardly protruding gland receiving the pointed end of the needle. The diaphragm is configured to provide a bellows-like zone surrounding the diaphragm gland and being capable of exing so as to permit the gland to be forced inwardly against the point of the needle. This effects at least a partial puncture by the needle before the ampoule is collapsed to effect an injection, thus avoiding any possibility of an hydraulic Patented Feb. 22, 1966 lock. Such a diaphragm is the subject of the patent, Dunmire Patent No. 3,094,988, referred to above.

Since the advent of disposable hypodermic ampoules of the type described, a considerable amount of effort has been devoted to the development of mechanical devices for actuating the ampoules to inject medicaments from the ampoules into persons or other animals. This is due to the fact that, for psychological reasons, and also to minimize the element of human error, hospitals have indicated a preference for using mechanical applicators to effect injections with such ampoules, even though, with reasonable care, the ampoules may be manually used without an applicator.

Several attempts have been made to develop mechanical applicators for ampoules of the type last described, but none has been successful prior to the present invention when used with ampoules having the type of diaphragm with the protruding gland to which Dunmire Patent No. 3,094,988 relates. One :applicator that was found to be unsatisfactory for this particular use, although highly satisfactory in other respects, irs described and claimed in a copending application Serial No. 129,763, led August 7, 1961, by Blumenstein and David, now Patent No. 3,094,121. Ampoules of the particular type last referred to above, which could be manually actuated satisfactorily, sometimes burst Ior leaked when used with the mechanical applicator of the Blumenstein and David patent.

The instant invention is primarily directed to improved mechanical applicators for use with hypodermic ampoules of the general type described herein and, particularly, for use with ampoules having the kind of diaphragm with a protruding gland that is disclosed and claimed in Dunmire Patent No. 3,094,988. The objects of the invention are to provide applicators which will effect proper actuation of the ampoules and produce consistently satisfactory injections without requiring any particular skill on the part of the person operating the applicator.

Except in the respect mentioned above, the general type lof applicator dis-closed and claimed in the Blumenstein and David lpatent is presently preferred, and it may easily be modified in accordance with the principles of the present invention. Accordingly, the present invention and the problems which it solved will be illustrated and further described herein as applied to the general form of applicator disclosed in the IBlumenstein and David patent. Such an applicator comprises an elongated, hollow body that houses a plunger system. An external arm or lever and `a trigger mechanism are provided to retract a spring-biased plunger within the housing into a cocked position against the for-ce of an actuating spring and to release or fire the plunger so that it is `forcibly driven by the spring down onto the upper end of the ampoule, whereby the ampoule is axially oompressed and the liquid medicament is ejected therefrom as the needle is projected into the patient.

While the plunger is retracted toward the upper end of the housing and is locked in its retracted position, the ampoule is inserted into a ring chamber in the lower end of the applicator from which the lower end of the plunger was withdrawn. The handle may then be brought down along the side of the body structure, but not squeezed, and the .applicator is then ready for firing.

The operation of this particular preferred structure of the mechanical applicator is carried out, as indicated above, by inserting the ampoule into the tiring chamber at the bottom of the body structure before bringing the handle down into the ready or -firing position after coc-king the applicator. The lower end of the ampoule applicator is then pressed against the skin of the patient and the applicator is triggered to release the actuating spring and drive the plunger downwardly, whereby the ampoule is collapsed by axial movement of the plunger against the top end ofthe ampoule.

When it was first sought to adapt the above-described applicator for use with an ampoule of the type last described above and having an outwardly projecting gland at the center of the diaphragm, a radial slot was cut in the lower end W-all :of the applicator to receive the diaphragm gland as the ampoule was inserted into the firing chamber. This end wall of the applicator was relatively `thin and permitted the gland to project therethrough and beyond its lower surface for engagement with the skin of the patient. It was expected that, upon ifiring of the applicator, the skin of the patient would force the gland inwardly, as desired during the initial phase of -collapsing the ampoule. However, for reasons hereinafter explained, this did not prove to 'be satisfactory and the ampoules frequently 'burst or leaked in the course of collapsing them lwith the applicator plunger.

The present invention principally involves a different configuration -of the lower end of the applicator so as to avoid this bursting and leaking problem.

In accordance with the present invention, means are provided for holding the diaphragm firmly against the lower end wall of an applicator firing chamber with the gland of the ampoule diaphragm projecting through an aperture or radial slot in this end wall. Instead of being flat over both its inner and outer surfaces, this end wall of the. applicator of the present invention is made externally concave, the depth of the concavity being a substantial portion of the projecting length of the diaphragm gland, but preferably slightly less than this projecting length. The gland aperture through the end wall of the firing chamber is desirably located substantially at the vertex of the external concavity.

Although only a relatively shallow, external concavity is required, the presence of such a concavity has been found to be critically important to the satisfactory operation -of an applicator with this type -o'f hypodermic ampoule. It is also important that the diaphragm of the ampoule, entirely around the diaphragm gland, be held firmly :against the inner surface of the end wall of the applicator when the periphery of the lower end of the applicator is pressed firmly against the skin of the patient.

When the lower end of the applicator of the present invention is pressed against the skin of the patient preparatory to firing Ithe applicator, the skin apparently is stretched and domes upwardly into the -concavity in the end of Ithe applicator so as t-o press firmly against the gland of the ampoule. As a result, the gland is actuated inwardly `as required for proper operation of the ampoule. As hereinafter more fully described with reference to the drawings forming a part of this application, the normal softness of the skin of the patient is such that it does not satisfactorily force the ampoule gland inwardly unless the skin is tensioned and domed upwardly in this manner by the periphery of the end of the applicator surrounding the concavity therein.

The foregoing and other objects, features, and advantages of the present invention will be better understood from the following detailed description of an illustrative embodiment and from the accompanying drawings.

In the drawings:

FIG. 1 is a longitudinal, sectional view of a complete mechanical Iapplicator made according to the present invention (the applicator being shown lying horizontally with its so-called l-ower end at the left, rfor convenience);

FIG. 2 is an elevation-al view of the lower portion of a mechanical applicator made according t-o the present invention, and the lower portion of a similar mechanical applicator not embodying the present invention, both shown in section and both being pressed against the arm of la human being;

FIG. 3 is a bottom view of the applicator depicted in FIG. 2, as indicated therein by the line 3 3;

FIG. 4 is an elevational view of a hypodermic ampoule embodying a preferred shell construction for use with mechanical applicators of the invention, part of `the ampoule being shown in cross-section for greater clarity; and

FIG. 5 is a fragmentary, vertical, cross-sectional view of a lower portion of the ampoule shown in FIG. 4, pointing out the dimensional relationship of the needle to the diaphragm structure.

Before describing in detail the applicator improvements of the present invention, reference is first made to FIG. 4, which illustrates the particular type of hypodermic ampoule for which the present invention was devised. It is to be understood at the outset that the specific construction of this ampoule forms no part of the present invention and will be described only for the purpose of facilitating an understan-ding of the applicator and its mode of operation.

As shown in FIG. 4, the hypodermic ampoule has a main body portion, generally designated 72, in the general form of an inverted cup-shaped shell defined by an upper end wall 73 and a circumferentially extending side wall. A peripherally outwardly extending flange 74 integrally extends around the open end or mouth of the body 72, and a disk-like diaphragm., generally designated 75, is sealed to this flange 74 so as to close the mouth of the body and form a fluid reservoir for containing the hypodermic liquid (not shown).

Enclosed entirely within the ampoule is a hypodermic needle, generally designated 75. In its preferred construction, the needle 76 has a circular, disk-like base 77 that is clamped adjacent the upper end wall 73 of the body 72 by a radially inwardly extending rib 78 so that a cannula 79 of the needle, which extends axially from the base of the needle, is in substantial alignment with the axis of the ampoule body and has its pointed end projecting downwardly in position to be forced through the diaphragm 75. A cannula op-ening (not shown) through the base 76 of the needle and into the adjacent butt end of the cannula permits the hypodermic liquid to be evacuated from the ampoule through the cannula after it lhas pierced the diaphragm.

As more specifically described in the copending application of Russell P. Dunmire, Serial No. 138,999, filed September 18, 1961, now Patent No. 3, 094,987, the body portion 72 is constructed so that at least 90% of the hypodermic liquid can be discharged from the ampoule when it is subject to an axially directed collapsing force of not more than l0 or l2 pounds. Provision is also made to prevent the ampoule body from elastically expanding back toward its original shape after it has once been collapsed, thereby avoiding the creation of a vacuum tending to suck or aspirate the hypodermic liquid back into the ampoule body.

As more specifically described in another copending application of Russell P. Dunmire, Serial No. 139,000, filed September 18, 1961, now Patent No. 3,094,987, the diaphragm is constructed to avoid a rapid build-up of hydraulic pressure within the liquid-filled shell and a consequent hydraulic lock which could result in the ampoule `body being ruptured before the hypodermic needle can be forced through the diaphragm at the initiation of an injection. Provision is also made to guide the hypodermic needle for entry into the skin in a direction substantially perpendicular thereto and to prevent an undesirable loss of the hypodermic liquid during an injection, as by leakage around the outside of the needle where it pierces the diaphragm. To these ends, the diaphragm 75 has an outer annular portion 81, a thick, elongated, centrally located, needle guiding and liquid sealing gland 82, and a relatively thin, flexible, corrugated, intermediate portion 83 connecting the gland and outer portion of the diaphragm 75 to permit relative movement therebetween. An axial, needle receiving passage 84 extends into the upper end of the gland from inside the ampoule diaphragm 75 and terminates short of the opposite, lower end vof the gland to Aform a thin, easily puncturable wall 85 closing the bottom of the passage. The lower end of the needle cannula 79 is slidably constrained within the passage with an interference t and with the pointed end 86 of the needle being normally spaced from the puncturable wall 85.

Due to the stiffness of the gland S2 and the length over which it contacts the needle, an effective, peripheral, liquid seal is maintained around the needle under the hydraulic pressure created during discharge of the ampoule. At the same time, the gland 82 is effective to support and pilot the needle during an injection. This guided movement of the needle minimizes the possibility of its being cocked and inserted at an oblique angle which might tear the skin and/or fail to penetrate to the required depth for an effective injection.

The thin, flexible, corrugated wall section 83 of the diaphragm 75 permits the gland 82 to move axially in- Wardly of the ampoule when the diaphragm is initially pressed against the skin, Because of this movement of the gland, the distance through which the pointed end 86 of the hypodermic needle 76 must travel before it pierces the diaphragm wall 85 and relieves the hydraulic pressure within the ampoule is relatively small. To the extent that inward movement of the gland 82 tends to reduce the interior volume of the liquid filled shell, the corrugated wall section S3 of the diaphragm is capable of bulging outwardly momentarily until the needle has punctured the diaphragm and provided an escape path through the needle for the liquid. Consequently, it is possible to provide sufficient clearance between the pointed end of the needle and the gland wall portion 85 to avoid accidental puncturing of the diaphragm during handling of the ampoule, and at the same time, to prevent the creation of an hydraulic lock at the 4start of an injection.

The hypodermic ampoule, including the body 72 and the diaphragm construction 75, may be made of any fiexible material which is inert and retains its strength when exposed to the hypodermic liquid and which will not rupture and/or tear as the ampoule is collapsed. Suitable materials include tough but relatively exible, elastomeric compounds, including plastics such as polyethylene and various other polyvinyl compounds and the like, a-nd plastic coated metal foils and uncoated metal foils which may be joined to form a leakproof liquid seal.

When, as in the preferred embodiment of the invention, the ampoule is made of plastic and the body 72 and diaphragm 75 are joined by heat sealing, the circumferential flange 74 of the body is preferably formed with an annular groove in which is seated a heat conducting metal ring 87. As more fully explained in the copending application of Russell P. Dunmire, Serial No. 252,272, filed January 15, 1963, the metal ring 87 facilitates a quick and localized application of heat to effect the heat sealing of the body flange 74 and the outer annular portion 81 of the diaphragm 75 so as to prevent the hypodermic liquid from being deleteriousfy affected by the heat and the material of the ampoule from being seriously weakened by overheating.

In use, for manual actuation (without an applicator), the ampoule is positioned with the diaphragm 75 against the skin, and an axially, inwardly directed force is applied to the upper end wall 73, preferably with the thumb. The initial application of pressure to the upper end wall forces the gland 82 inwardly relative to the body 72 and causes the pointed end 86 of the needle to penetrate the relatively thin gland wall S5. Continued application of pressure results in the hypodermic needle being inserted into the skin and the body 72 being collapsed so as to discharge substantially all of the hypodermic liquid through the needle.

The relative dimensions of the top and bottom sections T and B of the body are controlled in relation to the volume of the body so that, as it is being collapsed, the side wall portion of the top section of the body is progressively turned inside-out and nested within the bottom section with the upper rigid end wall 73 of the ampoule seated against the diaphragm 75. This collapsed conguration of the ampoule provides for a controlled evacuation of the hypodermic liquid well in excess of percent (eg, -97 percent by volume). Further, the preferred type of axial folding and progressive rolling collapse of the upper side wall as the top section of the body is inverted and moved within the bottom section enables the resulting high evacuation normally to be obtained with an applied force of only 4 or 5 pounds.

The applicators of the present invention are primarily designed to perform the foregoing operations in a generally similar manner by mechanically collapsing the ampoule while it is held in a firing chamber of an applicator and while the adjacent end of the applicator is held against the skin of the patient.

In the light of the foregoing, it can be better understood how recessing the lower or skin-contacting end of a mechanical applicator in accordance with the present invention overcomes the problems encountered when using a mechanical applicator which does not have a recessed contacting end. Referring to FIG. 2, there is depicted the lower portion of the body of a mechanical applicator 10 made according to the present invention and the lower portion of the body of a mechanical applicator 12 which does not conform to the present invention, both being in contact with the skin 13 of the arm 14 `of a human being. The mechanical applicator 10, having a recessed, concave end surface 15, causes the skin 13 to stretch and dome upwardly as the periphery 16 of the body structure 17 of the applicator is pressed against the skin. It appears that the stretched skin, becoming tense, resists any substantial indentation by an outwardly extending gland 18 of an ampoule 19, and thereby forces the gland 18 axially inwardly toward the point of the needle cannula 21 While the ampoule body is restrained against upward movement by a flange 2i). As force is applied to the upper end 22 of the ampoule 19 by a plunger 23, the needle cannula 21 is easily driven through the sealed end of the gland 18 before any substantial hydraulic pressure is developed within the ampoule.

By contrast, when the applicator 12 is pressed against the surface of the skin, the gland 18 depresses the untensioned skin at point 25, apparently meeting relatively little resistance, and the relatively short projecting length of the gland 18 seems to bury itself in the skin depression without being forced inwardly toward the point of the needle cannula 21. Apparently because the applicator 12, having a dat end 26, does not cause the skin 13 to dome upwardly and stretch and become tense, the necessary resistance needed to cou-ntermove the gland 18 is not developed.

While the foregoing comparison between the modified applicator of the present invention with a Hat-ended applicator is believed to explain correctly the reason for the success of the invention, it may not be the correct or the only reason for suc-h success. The comparison is given only as a theory, Whereas the improved results are known as fact.

As hereinbefore mentioned, the gland 82 performs several related functions, including cooperating with the corrugated wall section S3 of the diaphragm 75 to prevent the creation of an hydraulic lock, and slidably constraining the needle cannula 79 within the gland passage 84 so that the point of the needle is slightly spaced from the puncturable wall 85 to minimize an accidental puncture of the wall.

The desired cooperation between the needle and the gland and the rest of the diaphragm in performing these functions is primarily obtained by extending the gland 82 axially beyond the diaphragm, locating the puncturable wall 85 of the gland close to the lower, outer end thereof, and positioning the pointed end 86 of the needlenear the puncturable wall. The axial distance the gland 82 extends beyond the diaphragm and the relative position of the pointed end of the needle to the puncturable wall 85 are important considerations in designing the described ampoules and, consequently, in designing an applicator to embody the present invention.

By referring to FIG. 5, a better understanding will be obtained of the cooperating function between the needle and the gland and the rest of the diaphragm, and of the relationship these cooperating elements have to the recessed concavity in the end plate 67 of the mechanical applicator made according to the present linvention (see FIG. 2).

The distance the gland 82 extends beyond the diaphragm 75 is represented by x. This distance x must be great enough to permit inward'movement of the gland by pressing the gland againts a flat surface, preferably until the extreme tip of the needle point has at least passed through the puncturable wall 85 prior to axial movement of the needle itself. When the ampoule is placed in a mechanical applicator, the effective distance x of thel gland is diminished by the thickness z of the end plate 67 immediately surrounding the opening. After the ampoule has been inserted into the applicator, the effective length of the gland is equal to the difference between the distance x of the axial extension of the glandand the thickness z of the end plate surrounding the opening for the gland.

The space s between the wall 8Sy and the end 86 of the needle must be less than the distance determined by subtracting the thickness of the puncturable wall 85 from the amount of inward movement of the gland per-` mitted by the corrugated annular wall sect-ion 83. If the maximum extent of the glands inward movement is represented by y and the thickness of the puncturable Wall is represented by t, then s yt and therefore s+t y. Accordingly, the ampoule should be designed so that y is at least greater than t plus s. However, allowing for depression of the `skin by the tip of the gland and any yielding due to the flexibility of the ampoule shell material prior to penetration of the puncturable wall 85, a third value v must be added to f-i-s.

Therefore, ampoules which are to be used in mechanical applicators should be made with a gland extending axially from the diaphragm a distance great enough so that the gland extends beyond the inner portion of the recessed surface of the applicator end wall a distance greater than the sum of t, s, and v. In other words, x-z tjsjv.

' It has been found that the puncturable wall 85 of the ampoule should be about .01 inch thick in order to perform its ampoule closing function. The thickness of the wall 85, the spacing of the pointed end of the needle from the wall, and the overcoming of any small amount of yielding of the ampoule shell structure necessitate that the actual inward axial movement of the gland be at least .043 inch, and preferably about .045 inch, in order for the wall to be sufliciently punctured prior to axial movement of the needle itself.

The yielding of the `skin even when tense requires that the gland extend at least .070 inch, and preferably at least .O72 inch, axially from the vertex of the recessed concavity in the end wall of the mechanical applicator.

The recessed concavity in the end wall of the mechanical applicators of the present invention must be designed for use with an ampoule of specific dimensions. The axial depth of the recessed concavity depends partly on the inside diameter of the annular, skin-engaging terminal surface of the mechanical applicator, i.e., the diameter of the concavity, and may be correlated therewith. It has been found that the ratio of the axiall depth of the concavity to this diameter of the concavity is substantially a constant over a limited, preferred range of diameters (e.g., .25 inch to about 5 inches).

Ratios of the axial depth of the concavity to the inner diameter of the terminal skin-contacting surface, which preferably are used in designing the applicators of the present invention, range from about .046 to about .065, or slightly higher. If the ampoule has a gland structure extending axially from the diaphragm a distance proportionately greater than that described above for ampoules of similar size, this operable range of applicator dimension ratios may be extended to higher limits of depth to diameter of the concavity. For example, the axial depth of the concavity may be greater than .065 inch if the diameter of the concavity is 1.0 inch and the values for x and y (defined above) are sufciently great for obtaining at least a .043 inch axial movement of the gland.

Referring to FIG. l there is shown a preferred ernbodiment of a mechanical applicator constructed in accordance with the present invention. The applicator comprises an outer tubular shell or body 30, preferably closed at its upper end by a cap 31 and having an annular flange 32 adjacent its opposite end, extending radially inwardly and defining an opening 33. A plunger guide bushing 34 is inside the shell 30 adjacent its lower end and extends upwardly to a point just below a firing pin hole 35 which extends through the wall of the shell 30. Slidably `supported in the bushing 34 is a spring-actuated, ampoule-engaging plunger 36 having a lower ampouleengaging end portion 37 and an integral, annular flange 38 for controlling the movement of the plunger.

A second annular flange 38a, spaced longitudinally upwardly from flange 38, extends radially .outwardly from the plunger 36 in a plane parallel to flange 3S. Extending transversely inwardly from the left hand side of the plunger 36 through flange 38a is a bore 39 in which a piston 40 has a sliding lit. This piston includes a latch pin 41 of reduced diameter formed on its left hand end, and this pin is adapted to extend into and through a reduced diameter continuation 42 of the bore 39. A compression spring 43 is disposed behind the piston 40 in the bore 39 and is held in place by a pin 44. This spring 43 tends at all times to urge the piston 40 and its latch pin 41 to the left to a plunger locking position. Movement ofthe latch pin 41 to the left, however, is limited by the engagement of the left hand end of the piston 40 with the left hand end of the bore 39, permitting the latch pin 4l to extend slightly into the firing pin hole 35, but not beyond the youter wall of the shell 30. When in this locking position, the latch pin 41 will engage the ring pin hole 35, thus locking the plunger 36 in a cocked position against downward movement.

A cylindrical stem or shank portion 45 is integrally formed with and extends upwardly from the body of the plunger 36. This shank portion 45 has a sliding fit within a downwardly extending tubular portion 46 -of a springcompressing slide member 47. Extending through the wall of the tubular portion 46 are opposed, elongated slots 48 and 49 and the ends of a guide pin 49a. The guide pin 49a, secured in the upper end of the shank 45, extends therethrough to project into the slots 48 and 49. These slots, acting as guides, thus form a lost motion connection between the plunger 36 and the slide member 47.

The spring-compressing slide member 47 has an enlarged upper end forming a cylindrical piston having a sliding t in an upper guide bushing 50. This blushing is secured within the outer shell or body 30, and a transverse slot 51 is formed in the upper end of the slide member 47 to form a yoke receiving a first toggle link 52, which has a pivotal connection at one end in the slot 51 on a pivot pin 53.

A second toggle link member 54 is pivotally mounted on a pin 55 which is mounted transversely across the body 30 and is supported in apertures (not-shown) formed in the bushing 50. The toggle link member 54 is thicker than the toggle link S2 and is shaped below the pin 55 to provide a yoke receiving the upper end of the lower toggle link 52. The two toggle links 52 and S4 are pivotally connected together at a common pivot point by a pin 56.

The toggle link 54 has a curved, upper, outer edge 57 formed on a radius about the center of the pin 55, and the right-hand side of the toggle arm 54 extends out through a slot 58 in the bushing Si) and the outer shell 30. The upper end of the slot 58 closely iits the outer curved edge 57 .of the toggle link 54.

Preferably integrally formed with the toggle link 54 and extending downwardly from the outer portion thereof is an operating handle 59, which is preferably channel shaped in cross section to give the desired strength and rigidity without excessive weight. The lower end portion of the handle 59 is turned inwardly to provide a iiange 60 (see lett side of FIG. l) having a semi-circular end configuration complementary to a semi-annular ilange 62, the latter being secured, as by welding, to the inner surface of the shell 3i). The flanges 60 and 62 cooperate, when the handle 59 is in the position shown in FIG. l, to form a substantially complete annulus 61 parallel to and spaced from a lower end wall of the shell 30 (to be described) for holding an ampoule 19 in place prior to firing the applicator.

A tiring pin 64 is secured to the handle S9 in position to enter the tiring pin hole 35 in the outer shell 30 when the handle 59 is moved into the tiring position.

Extending between the upper end of the plunger 36 and the lower end of the spring compressing slide member 47, and tending to move the same apart, is a compression spring 65. This is a coil spring which is adapted to be compressed against the retracted and latched plunger 36 and, when this plunger is released, to supply the force necessary to collapse the ampoule, force the hypodermic needle into the patient, and discharge the medicament through the needle.

The wall of the outer shell 30 extends downwardly from the flange 32 to define a ng chamber, but is cut away at one side, as indicated at 66, to permit the insertion of an ampoule 19 into firing position. A bottom ampoule-retaining end wall or plate 67, having a at inner surface and an outer, annular skin-engaging terminal surface surrounding a recessed or concave surface, is also cut away, on the same side as the shell 30, so as to provide a centering slot 68 (see FIG. 3), which receives a gland 18 of an ampoule 19 with a close sliding fit and facilitates location :of the ampoule in the tiring chamber while permitting the above-described inward movement of the ampoule gland 18 and ejection of the hypodermic needle 21 therethrough.

Referring to FIG. 3, there are shown the cut-away opening 66 in the cylindrical wall of the shell 30 and the cut-away, gland-receiving slot 68 in the end plate 67, which permit sliding of an ampoule 19 into the firing chamber of the applicator. The ampoule 19a and gland 18a (both shown in phantom) illustrate an ampoule moving into position in the tiring chamber. A radially, inwardly extending, annular flange arrangement, comprising the semi-annular portions 60 .and 62 described above, holds the ampoule rmly in place against the end plate 67 so that the ampoule is substantially axially aligned with the body structure of the applicator and the gland 18 of the ampoule projects outwardly beyond the outer, central surface portion of the recessed end plate.

Prior to tiring of the applicator, the ampoule-retaining ange portions 60 and 62 are spaced slightly apart at their adjacent ends, as shown at 92 in FIG. 3, after the handle 59 has been swung outwardly and upwardly to cock the applicator for tiring and has then been returned to the tiring position shown in FIG. 1. This permits the required inward tiring movement of the handle 59 (hereinafter described), during which the adjacent ends of the ange portions 60 and 62 are brought into substantial engaget0 ment and the gap 92 therebetween is substantially eliminated.

The operation of the above-described mechanism is as follows. To set the device for an injection operation, the operator grasps the applicator body in one hand and the handle 59 in the other and manually swings the handle outwardly and upwardly into a retracted position, breaking the toggle formed by the links 52 and S4 and causing the spring compressing slide member 47 to move upwardly in its plunger retracting direction in the bushing 34. After a Certain initial upward movement of the slide member 47, during which the plunger 36 remains in its downward position, the lost motion between the plunger 36 and the slide member 47 is taken up, and the bottom ends of the slots 48 and 49 in the tubular portion 46 of the slide member engage the ends of the pin 49a in the plunger shank 4S. Further upward movement of the slide member 47 will then lift the plunger 36 against the biasing force of the spring 65. When the handle 59 reaches its full retracted position at the limit of its outward stroke, which is determined by engagement of the side of the toggle link 52 with the bottom end of the slot 58 in the side Wall of the housing, the latch pin 41 in the plunger 36 will have been moved upwardly, permitting the spring 43 to push the pin 41 out into its extended or locking position in hole 35. During this outward swinging of the handle 59, the distance between the upper end of the plunger 36 and the under side of the spring-compressing slide 47 is increased, thus permitting the spring 43 to expand correspondingly.

After the handle 59 has been swung into position away from the body structure 30, the ampoule is inserted into the applicator so that the outer flange of the ampoule ts between the semi-annular ange 62 and the applicator end plate 67. The handle 59 is then moved downwardly and inwardly toward the applicator body 3G, bringing the complementing semi-annular flange 60 into place, as shown in FIG. 1 thereby lirmly holding the ampoule against the flat inner surface of the end plate 67. As the plunger 36 is locked against downward movement by the pin 41 engaging the hole 35, the spring 65 remains cornpressed. When the handle is squeezed against the body 30, the tiring pin 64 engages and pushes the latch pin 41 inwardly against the spring 43 until the latch pin clears the hole 35, When this occurs, the compressed spring 65 immediately moves the plunger 36 and its end portion 37 forcibly downwardly against the upper end 22 of the ampoule 19, causing same to be collapsed .as described above, and driving the hypodermic needle cannula 21 through the ampoule gland 18 and into the patient. As previously explained, as the ampoule is collapsed, the fluid therein is forced out through the needle cannula 21. By properly proportioning the dimensions of the parts of the applicator, the strength of the spring 65, etc., the device will function as described, in a uniform and most desirable manner. The unloading and recocking operations are rapidly and easily accomplished by merely swinging the handle 59 out. After the mechanism is placed in its cocked position, it will not be tired until the handle is squeezed against the body 30 to release the firing pin.

In addition to the specic plunger cooking and firing mechanism illustrated and described herein, other mechanisms for applying a collapsing pressure against the ampoule to perform injections therewith are envisaged such as, for example, gas pressured pistons or magnetic devices such as solenoid actuated pistons, and even mild explosives. The all important consideration in the design of the applicators to be used for injections with the abovedescribed ampoule is that of recessing the skin-contacting surface of a skin-engaging plate and providing means to hold the diaphragm or base of the ampoule firmly against the opposite side of that plate.

It is not intended that the present invention be limited by the specific details shown and described, and it is l i intended to include all embodiments of the invention falling within the scope of the appended claims.

Wha-t is claimed is:

1. An ampoule applicator particularly suited for use with a hypodermic ampoule having a needle housed therein and having a diaphragm adapted to be punctured by the needle and including an outwardly projecting diaphragm gland embracing a pointed tip of the needle, said applicator comprising a hollow body defining :an ampoulereceiving chamber adjacent yone end thereof, said end of said applicator body being adapted to contact an area of the skin of .a patient which is to be injected and including an end Iwall defining an opening through which said gland of the ampoule diaphragm may project, means -for retaining the ampoule against said end wall and for maintaining the gland of the ampoule in said opening, means in said body for exerting pressure on an ampoule contained in said chamber in engagement with said end wall for effecting an injection while projecting the needle through the opening 4in said end Wall, the interior of said end wall being flat for direct engagement by the ampoule diaphragm prior t-o exert-ing pressure on the lampoule and, said end wall being externally configured [to provide an annular, skin-engaging, terminal surface surrounding a recessed surface containing said gland-receiving opening, said recessed surface having an -axial depth to diameter ratio in the range from about 0.046 to about 0.065.

2. In an .ampoule applicator particularly suited for use with a hypodermic ampoule having a needle housed therein and having a diaphragm adapted to be punctured by the needle, said applicator comprising a hollow body having an end wall defining one end of an ampoule receiving chamber and being recessed to define an external concavity, plunger means mounted in said hollow body for engaging an ampoule in said chamber and collapsing it against said end wall, and means for actuating said plunger, the improvement wherein the inner surface of said end wall is flat in a plane substantially normal to the axis of the body, and wherein said applicator includes means in said body and spaced from and cooperating with said fiat surface to hold the diaphragm of the ampoule against said flat surface, and wherein the ratio of the axial depth to the Awidest transverse dimension of said external concavity -is in the range of about 0.046 to about 0.065.

3. In an ampoule applicator particularly suited for use with a hypodermic ampoule having a needle housed therein and having a diaphragm adapted to be punctured by the needle, said applicator comprising a hollow body having a transverse end -wall deiining one end of an ampoule receiving chamber, and having an opening through which the needle of the -ampoule can pass, and being recessed to define an external concavity, plunger means mounted in said hollow body for engaging an ampoule placed in said chamber and collapsing it against said' end wall to drive the needle through said opening, and means for actuating said plunger, the improvement wherein the inner surface of said end wall is fiat in a plane substantially normal to the axis of the body, said body has means t-o retain the ampoule against the inner surface of said end wall, .and the ratio of the axial depth of the concavity at its vertex to the diameter of the concavity being in the range of from about .045 to about .065.

4. In an -ampoule applicator for use with a hypodermic ampoule having a needle housed therein Iand the -ampoule having a wall to be punctured by the needle,

a hollow body having a transverse wall extending across one end,

said transverse wall having an internal surface configured to support ya hypodermic ampoule and having an opening to permit passage of the needle of the ampoule,

means carried by the body to hold the ampoule against said internal surface at all times,

means within said body for engaging an ampoule placed against said transversewall to move the needle through said opening,

and the outer surface of said transverse wall being configured as a skin-stretching concavity having a diameter in the range of 0.25-5 inches and an axial depth to diameter ratio in the range of about 0.046-0065.

5. In an ampoule applicator for use with a hypodermic ampoule having a needle housed therein and the ampoule having a diaphragm adapted to be punctured bythe needle and including an outwardly projecting diaphragm gland embracing a pointed tip of the needle,

a hollow body including an end wall defining an ampoule-receiving chamber adjacent one end of the hollow body,

said end wall having an opening through which the gland of the ampoule may project,

means within said body for exerting pressure on an ampoule vcontained in said chamber and in engagement with said end wall, for effecting an injection into a patient while projecting the needle through said opening in said end wall,

the interior of said body being coniigured to support and maintain the ampoule diaphragm against said end wall with the gland extended through said wall opening and to resist inward axial movement of said diaphragm,

and said end wall being externally configured as a skin stretching concavity having a ratio of the axial depth to the widest transverse dimension within the range of about 0.046 to about 0.065.

y6. In an ampoule applicator for use with a hypodermic ampoule having a needle housed therein and having a diaphragm adapted to be punctured by the needle and including an outwardly projecting diaphragm gland embracing a pointed tip of the needle Ito be punctured by the needle on initial movement of the needle Iand gland relative to one another,

a hollow body defining an ampoule-receiving chamber adjacent one end thereof,

said end of said hollow body including an end wall defining an opening through which the gland of the ampoule may project,

means within said body for exerting pressure on an Iampoule contained in said chamber in engagement with said end wall for effecting an injection while projecting the needle through the opening in said end wall,

the interior of said body being configured to x the ampoule diaphragm in said chamber with the gland extended through said wall opening and to resist in- Ward movement of the diaphragm away from said Wall opening,

and said end wall being externally configured as a skinstretching concavity having an axial depth to diameter ratio within the range of about 0.046 to about 0.065, whereby contact of said gland with the skin of a patient in combination with stretching of the4 skin by said concavity causes the needle of the am-- poule to `at least contact said diaphragm gland in a puncturing manner prior to actuation of said pressure exerting means.

References Cited by the Examiner UNITED STATES PATENTS 6/1959 Dunmire 12S-218 6/1963 Blumenstein et al. 12S- 218 

3. IN AN AMPOULE APPLICATOR PARTICULARLY SUITED FOR USE WITH A HYPODERMIC AMPOULE HAVING A NEEDLE HOUSED THEREIN AND HAVING A DIAPHRAG, ADAPTED TO BE PUNCTURED BY THE NEEDLE, SAID APPLICATOR COMPRISING A HOLLOW BODY HAVING A TRANSVERSE END WALL DEFINING ONE END OF AN AMPOULE RECEIVING CHAMBER, AND HAVING AN OPENING THROUGH WHICH THE NEEDLE OF THE AMPOULE CAN PASS, AND BEING RECESSED TO DEFINE AN EXTERNAL CONCAVITY, PLUNGER MEANS MOUNTED IN SAID HOLLOW BODY FOR ENGAGING AN AMPOULE PLACED IN SAID CHAMBER AND COLLAPSING IT AGAINST SAID END WALL TO DRIVE THE NEEDLE THROUGH SAID OPENING, AND MEANS FOR ACTUATING SAID PLUNGER, THE IMPROVEMENT WHEREIN THE INNER SURFACE OF SAID END WALL IS FLAT IN A PLANE SUBSTANTIALLY NORMAL TO THE AXIS OF THE BODY, SAID BODY HAS MEANS TO RETAIN THE AMPOULE AGAINST THE INNER SURFACE OF SAID END WALL, AND THE RATIO OF THE AXIS DEPTH OF THE CONCAVITY AT ITS VERTEX TO THE DIAMETER OF THE CONCAVITY BEING IN THE RANGE OF FROM ABOUT .045 TO ABOUT .065. 